Friday, February 27, 2009
Pieces of Mind - Kyoto Protocol
Global models that include the feedbacks between climatic change and the carbon cycle have all shown decreased carbon sinks over the next century. 
Growing trees absorb net quantities of CO2, and the higher levels of CO2 and nitrogen in the atmosphere are themselves stimulating tree and plant growth…. But the researchers expect these effects to reach saturation point and cease to have an effect. 
What the researchers found limited the trees' capacity to respond to carbon fertilisation was a shortage of other nutrients, especially nitrogen. The availability of water was also important. ….The US and the other members of the so-called Umbrella Group (Japan, Switzerland, Canada, Australia, Norway, New Zealand and Russia) wanted to rely considerably on sinks in meeting their Kyoto targets for reducing emissions of greenhouse gases that may be warming the global climate. The European Union and others opposed this, arguing that open-ended use of sinks to absorb CO2 could allow countries to avoid making any actual emission cuts at all. 
[Tree] respiration increases in response to temperature rises, which are triggered by the rising levels of CO2. Many scientists believe that respiration may be about to accelerate, turning the forests from sinks to sources of carbon…. They failed to recognise that this could happen because, although CO2 take-up is instantaneous, the warming that triggers respiration has a built-in delay of about 50 years, mainly because of the oceans' thermal inertia. So planting more trees could soon prove a quick way of speeding up climate change, not of moderating it. Bob Scholes, of the South African Government's research agency, CSIR, says it could be a costly mistake. "The carbon cycle has a very long equilibrium time. The consequences of actions taken now will persist for many centuries." 
 The First State of the Carbon Cycle Report (SOCCR)
The North American Carbon Budget and Implications for the Global Carbon Cycle
The Carbon Cycle in Land and Water Systems, Part III Overview.
Lead Author: R.A. Houghton, Woods Hole Research Center
 Forests 'only temporary carbon absorbers'.
Wednesday, 7 November, 2001, 19:13 GMT
By Alex Kirby. BBC News Online environment correspondent
 Tree planting warning over global warming
Tree at sunset BBC
Trees may not live up to expectations for storing carbon dioxide
By BBC News Online's environment correspondent Alex Kirby
 Trees 'will not avert climate change'
Wednesday, October 20, 1999 Published at 22:49 GMT 23:49 UK
The world's forests can buy a little time, before they start adding to the warming
By Environment Correspondent Alex Kirby